Enable M = Mary's age now So Mike's age is 3M 3M + 4 = 2 (M + 4) = 2M + 8 Now, subtract 2M from the two factors. then you definitely have: M + 4 = 8 or M = 4 examine: Mike is now 12. In 4 years, Mary would be 8 and Mike would be sixteen.
Answer:
The correct answer is 218 math textbooks and 259 sociology textbooks.
Step-by-step explanation:
To solve this problem, we can make a system of equations. Let the number of sociology textbooks sold be represented by the variable "s" and the number of math textbooks sold be represented by the variable "m". Using these variables, we can make two equations:
s + m = 477
m + 41 = s
There are many ways to solve this system of equations. One approach we can take is substituting the value for s given by the second equation into the first equation. This is modeled below.
s + m = 477
(m + 41) + m = 477
Combining like terms on the left side of the equation yields:
2m + 41 = 477
Subtracting 41 from both sides of the equation gives us:
2m = 436
Finally, dividing both sides of the equation by 2 gives us:
m = 218
To solve for the number of sociology textbooks, we can substitute into either of our original equations.
m + 41 = s
(218) + 41 = s
s = 259
Therefore, your answer is m = 218 and s = 259, or 218 math textbooks and 259 sociology textbooks were sold.
Hope this helps!
The passenger travelled 12 miles
2x-y=7
y=2x+3
Substitute (2x+3) in for y in the first equation
2x-(2x+3)=7
2x-2x-3=7
-3=7
Becuase -3 does not equal 7 the answer is no solution
20x+30y= c(total cost of money)
Part B: 20(10)+5(30)
200+150=$350
